The present invention relates to a forming station for the production of hollow articles of vitreous material which includes at least one forming means i.e., a forming tool or a mold, and for each forming means a neck ring means carrying a parison and including a pair of neck ring halves and an integral guide ring coaxially carried by the neck ring halves and rotatable relative thereto so that relative rotary movement is imparted to the parison carried by the neck ring relative to the remainder of its forming means.
In a known forming station of the aforementioned kind (German Offenlegungsschrift No. 2,243,429) an integral guide ring is connected by pin-and-slot connections with a three-part neck ring for rotation with the same. Each neck ring part is rotated by means of an annular gear coaxially mounted with the neck ring and connected thereto for rotation therewith. The teeth of the annular gear mesh with the teeth of a gear which is mounted at the forming station turnable about its axis and a sprocket gear is coaxially mounted with the last-mentioned gear and connected thereto for rotation about a common axis. The chain gear is engaged with a sprocket chain which is driven by an additional sprocket gear. Upon rotation of the last-mentioned sprocket gear the neck ring and the guide ring therein will therefore be rotated relative to the remaining forming tool, for instance a mold coaxially mounted with the neck ring.
This known arrangement has the disadvantage that it comprises a relatively large number of complicated and expensive components. This leads to trouble during the rough operating conditions such forming stations are subjected to and this also makes proper maintenance and repair of the forming station rather difficult. Since during use of a plurality of forming stations the aforementioned sprocket gears are in mesh with the sprocket chain, all neck rings will be rotated simultaneously. A selective rotation of only one neck ring is not possible. Furthermore, only a single forming tool can be provided at each of the above-described forming stations. Since the neck ring is turned synchronously with the guide ring coaxially mounted therein, a desirable positive clamping of the neck ring on the remaining forming tool, for instance a mold, is not possible. To the contrary, a more or less wide gap has to be maintained between the mold and the neck ring which leads to undesirable fins or seams on the finished hollow glass article and also necessarily to a limiting of the pressure of the blowing medium.